1. Field of the Invention
This invention relates broadly to endoscopic surgical instruments. More particularly, this invention relates to an actuation handle for an endoscopic biopsy forceps instrument with means for facilitating sample removal without withdrawal of the biopsy forceps instrument from an endoscope.
2. State of the Art
Endoscopic biopsy procedures are typically performed with an endoscope and an endoscopic biopsy forceps device (bioptome). The endoscope is a long flexible tube carrying fiber optics and having a narrow lumen through which the bioptome is inserted. The bioptome typically includes a long flexible coil having a pair of opposed jaws at the distal end and manual actuation means at the proximal end. Manipulation of the actuation means opens and closes the jaws. During a biopsy tissue sampling operation, the surgeon guides the endoscope to the biopsy site while viewing the biopsy site through the fiber optics of the endoscope. The bioptome is inserted through the narrow lumen of the endoscope until the opposed jaws arrive at the biopsy site. While viewing the biopsy site through the fiber optics of the endoscope, the surgeon positions the jaws around a tissue to be sampled and manipulates the actuation means so that the jaws close around the tissue. A sample of the tissue is then cut and/or torn away from the biopsy site while it is trapped between the jaws of the bioptome. Keeping the jaws closed, the surgeon withdraws the bioptome from the endoscope and then opens the jaws to collect the biopsy tissue sample.
A biopsy tissue sampling procedure often requires the taking of several tissue samples either from the same or from different biopsy sites. Unfortunately, most bioptomes are limited to taking a single tissue sample, after which the device must be withdrawn from the endoscope and the tissue collected before the device can be used again to take a second tissue sample. Several attempts have been made to provide an instrument which will allow the taking of several tissue samples before the instrument must be withdrawn and the samples collected. Problems in providing such an instrument include the extremely small size required by the narrow lumen of the endoscope and the fact that the instrument must be flexible in order to be inserted through the lumen of the endoscope. Thus, several known multiple sample biopsy instruments are precluded from use with an endoscope because of their size and rigidity. These include the xe2x80x9cpunch and suction typexe2x80x9d instruments disclosed in U.S. Pat. No. 3,989,033 to Halpern et al. and No. 4,522,206 to Whipple et al. Both of these devices have a hollow tube with a punch at the distal end and a vacuum source coupled to the proximal end. A tissue sample is cut with the punch and suctioned away from the biopsy site through the hollow type. It is generally recognized, however, that dry suctioning tissue samples (i.e., without the use of an irrigating fluid) through a long narrow flexible bioptome is virtually impossible.
Efforts have been made to provide multiple sampling ability to an instrument which must traverse the narrow lumen of an endoscope. These efforts have concentrated on providing a cylindrical storage space at the distal end of the instrument wherein several tissue samples can be accumulated before the instrument is withdrawn from the endoscope. U.S. Pat. No. 4,651,753 to Lifton, for example, discloses a rigid cylindrical member attached to the distal end of a first flexible tube. The cylindrical member has a lateral opening and a concentric cylindrical knife blade is slidably mounted within the cylindrical member. A second flexible tube, concentric to the first tube is coupled to the knife blade for moving the knife blade relative to the lateral opening in the cylindrical member. A third flexible tube having a plunger tip is mounted within the second flexible tube and a vacuum source (a syringe) is coupled to the proximal end of the third tube. A tissue sample is taken by bringing the lateral opening of the cylindrical member upon the biopsy site, applying vacuum with the syringe to draw tissue into the lateral opening, and pushing the second flexible tube forward to move the knife blade across the lateral opening. A tissue sample is thereby cut and trapped inside the cylindrical knife within the cylindrical member. The third flexible tube is then pushed forward moving its plunger end against the tissue sample and pushing it forward into a cylindrical storage space at the distal end of the cylindrical member. Approximately six samples can be stored in the cylindrical member, after which the instrument is withdrawn from the endoscope. A distal plug on the cylindrical member is removed and the six samples are collected by pushing the third tube so that its plunger end ejects the samples.
The device of the Lifton patent suffers from several recognizable drawbacks. First, it is often difficult to obtain a tissue sample laterally of the device. Second, in order to expedite the obtaining of a lateral sample, a syringe is used to help draw the tissue into the lateral opening. However, this causes what was once a two-step procedure (position and cut), to become a three-step procedure (position, suction, cut). In addition, the use of a syringe requires an additional hand. Third, the Lifton patent adds a fourth step to the biopsy procedure by requiring that the tissue sample be pushed into the storage space. Thus, in all, the Lifton patent requires substantial effort on the part of the surgeon and an assistant and much of this effort is involved in pushing tubes, an action which is counter-intuitive to classical biopsy sampling. The preferred mode of operation of virtually all endoscopic tools is that a gripping action at the distal end of the instrument is effected by a similar action at the proximal end of the instrument. Classical biopsy forceps jaws are closed by squeezing a manual actuation member in a syringe-like manner.
A more convenient endoscopic multiple sample biopsy device is disclosed in U.S. Pat. No. 5,171,255 to Rydell. Rydell provides a flexible endoscopic instrument with a knife-sharp cutting cylinder at its distal end. A coaxial anvil is coupled to a pull wire and is actuated in the same manner as conventional biopsy forceps. When the anvil is drawn into the cylinder, tissue located between the anvil and the cylinder is cut and pushed into a storage space within the cylinder. Several samples may be taken and held in the storage space before the device is withdrawn from the endoscope. While the device of Rydell is effective in providing a multiple sample tool where each sample is obtained with a traditional two-step procedure (position and cut), it is still limited to lateral cutting which is often problematic. Traditional biopsy forceps provide jaws which can grasp tissue frontally or laterally. Even as such, it is difficult to position the jaws about the tissue to be sampled. Lateral sampling is even more difficult.
A multiple sample biopsy forceps of a more traditional form is disclosed in co-owned U.S. Pat. No. 5,542,432 to Slater et al. Slater et al. discloses an endoscopic multiple sample biopsy forceps having a jaw assembly which includes a pair of opposed toothed jaw cups each of which is coupled by a resilient arm to a base member. The base member of the jaw assembly is mounted inside a cylinder and axial movement of one of the jaw assembly and cylinder relative to the other draws the arms of the jaws into the cylinder or moves the cylinder over the arms of the jaws to bring the jaw cups together in a biting action. The arms of the jaws effectively form a storage chamber which extends proximally from the lower jaw cup and prevents accumulated biopsy samples from being squeezed laterally out from between the jaws during repeated opening and closing of the jaws and the lower jaw cup enhances movement of the biopsy samples into the storage chamber. The device can hold up to four samples before it must be retrieved out of the endoscope. However, in some biopsy procedures it is sometimes desirous to retrieve more. In addition, it has been found that samples within the chamber can stick together and make determinations of which sample came from which biopsy site somewhat difficult.
U.S. Pat. No. 5,538,008 to Crow discloses a multiple sample bioptome which purposes to take several samples and to transfer each sample by water pressure through a duct to the proximal end of the instrument, where each sample can be individually retrieved. The device includes a plastic jaw set biased in an open position and coupled to the distal end of an elongate tube, up to seven feet long. The tube defines a duct. A sleeve extends over the tube and a water flow passage is provided between the tube and the sleeve. An aperture is provided in the tube to permit the water flow passage to meet the duct at the distal end of the tube. Withdrawing the tube into the sleeve is disclosed to force the jaws closed and enable a sample to be cut from tissue and lodge in the duct. The water flow passage is disclosed to enable water to flow under pressure from the proximal end of passage to the distal end of the passage, through the aperture and into the distal end of the duct and to be aspirated to the proximal end of the duct, thereby transferring with it any sample contained in the duct to the proximal end where the sample can be retrieved.
While on paper the Crow device is appealing, in practice the design is impractical and flawed. For example, it would be very difficult, if not impossible, to slide the elongate tube, up to seven feet in length, relative to a sleeve of substantially the same length. It would also be difficult to maintain an unobstructed water flow passage between the tube and sleeve as the tube and sleeve curve and bend through the body. Furthermore, in order for the jaws to cut a tissue sample, the tube and jaws must be drawn into the sleeve, thereby undesirably pulling the jaws away from the tissue to be sampled.
It is therefore an object of the invention to provide an endoscopic biopsy forceps instrument which permits numerous tissue samples to be taken from a patient without removing the forceps form within the patient.
It is another object of the invention to provide an endoscopic biopsy forceps instrument which can individually retrieve each of several tissue samples from the forceps without removing the forceps from the patient.
It is also an object of the invention to provide an endoscopic biopsy forceps instrument which irrigates the forceps and aspirates tissue samples contained therein.
It is an additional object of the invention to provide an endoscopic biopsy forceps instrument which includes a proximal actuation handle having a chamber to retain tissue samples aspirated through the instrument.
It is a further object of the invention to provide an endoscopic biopsy forceps instrument which includes a proximal actuation handle for an endoscopic biopsy forceps instrument which includes a control means for controlling the aspiration and irrigation of fluid through the instrument.
In accord with these objects which will be discussed in detail below, an endoscopic biopsy forceps instruments is provided and generally includes a proximal actuation handle, a distal forceps assembly, a control member coupled to the proximal actuation handle and the distal forceps assembly, and a flexible multi-lumen tubular member having an irrigation conduit, an aspiration conduit, and a control conduit which receives the control member.
According to a preferred embodiment of the invention, the proximal actuation handle includes a shaft and a spool slidably mounted on the shaft. The actuation handle is also provided with a proximal irrigation passage, a sample chamber, a sample catch member, and a pinch valve which regulates irrigation and aspiration. The proximal irrigation passage is coupled to the irrigation conduit and to an irrigation coupling tube. The sample chamber is coupled to the aspiration conduit and to an aspiration coupling tube. The sample catch member includes a screen which is inserted into the sample chamber and filters out tissue samples from the aspirated fluid. The irrigation coupling tube and the aspiration coupling tube extend through the pinch valve which operates to control the flow of fluid through the tubes. The actuation handle is coupled to the proximal ends of both the flexible tubular member and the control member and moves the control member relative to the tubular member.
The distal assembly is coupled to the distal end of the tubular member and includes a hollow jaw cup coupled over the distal end of the aspiration conduit and a hollow movable jaw pivotally coupled adjacent the irrigation conduit. The jaw cup is preferably formed from a hard plastic and has a blunt cutting surface, while the moveable jaw is preferably a metal jaw with a sharp cutting edge. The movable jaw is further coupled to the control member, such that actuation of the actuation handle moves the movable jaw relative to the jaw cup, and thereby moves the jaws from an open position to a closed position. Moving the hollow jaws to a closed position provides a substantially fluidtight coupling between the irrigation and aspiration conduits.
It will be appreciated that the distal end of the instrument is brought into contact with tissue of which a sample is required and the actuation handle is actuated to close the jaws and cut off a tissue sample. With the jaws in a closed position, water is irrigated through the irrigation conduit to the jaws at the distal end of the instrument and aspirated from the jaws to the proximal end of the instrument through the aspiration conduit, such that the sample cut by the jaws is aspirated with the water. As the water is aspirated it passes through the chamber and the sample is filtered onto the screen. The screen may easily be removed to retrieve the sample. It will be further appreciated that the entire procedure of cutting a sample and retrieving the sample may be performed without removing the endoscopic biopsy forceps instrument from its location within this body.
According to one embodiment of the biopsy forceps instrument, the tubular member is ovoid in shape and defines a control conduit, an irrigation conduit, and an aspiration conduit. The distal forceps assembly includes a movable jaw, and a substantially rigid molded collar which is provided with a proximal socket-like coupling means for coupling the tubular member thereto, a fixed jaw cup, a distal irrigation passage, and a control passage. The collar is of similar diameter to the endoscope and is designed to be coupled to the outside of the distal end of an endoscope by a silicone rubber sock. The movable jaw is pivotally mounted on the molded collar and is movable relative to jaw cup. The tubular member is coupled in the socket. A control wire extends through the control conduit and the control passage is coupled to the two holes in the movable jaw.
According to a second embodiment, the biopsy forceps instrument includes a tubular member which defines an aspiration conduit having a circular cross section, an irrigation circuit having a kidney-shaped cross section, and two controls conduits. The distal assembly includes a stationary jaw bonded to the distal end of the tubular member, and a movable jaw. The stationary jaw includes a hollow jaw cup, a clevis member and two proximal ramps. The jaw cup is located over the aspiration conduit, and the clevis and the proximal ramps extend from the jaw cup over the irrigation conduit. The movable jaw is coupled to the clevis and is guided along the proximal ramps. The two controls conduits exit the distal end of the tubular member lateral of the proximal ramps. A central portion of a control member is coupled to the movable jaw and each end of the control member extends through the control conduits to the proximal end of the instrument.
According to a third embodiment of the biopsy forceps instrument, the instrument includes a tubular member which defines an aspiration conduit having a circular cross section and an irrigation conduit having a crescent-shaped cross section. The distal assembly is substantially similar to the second embodiment. The proximal ramps but and partially cover the irrigation conduit to define two entrances into the irrigation conduit for the control members. A distal end of each control member is coupled to the moveable jaw and the control members extend through the entrances and into the irrigation conduit. The entrances are sufficiently small such that when the jaws are in a closed position and fluid is irrigated through the irrigation conduit to the distal assembly, substantially all of the fluid passes through the irrigation conduit and into the jaws; i.e. only an insubstantial amount of the fluid irrigated through the irrigation conduit exits through the entrances formed by the ramps.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.